The invention relates to an optical element deformation system in an imaging device for the purpose of eliminating image errors or for active adjustment.
Very high imaging accuracies are required in many optical fields, in particular in micro-lithography. The aim is to minimize image errors even more. One of the main causes of image errors in this case is deformations of the optical elements. Such deformations can be introduced via mounts or be produced by mounts. Weight forces on optical elements can also lead to deformations and thus to image errors.
Reference is made to WO 97/34171 in relation to the general prior art.
Moreover, the precise adjustment of an imaging device, for example a projection lens, also requires individual optical elements to be actively adjusted in order, for example, to compensate errors in the lens in this way, or else to correct mounting inaccuracies.
It is the object of the present invention to create a system of the type mentioned at the beginning with the aid of which specific deformations can be undertaken on an optical element in a very comprehensive way, and/or very specific and sensitive active adjustments are also possible.